eggs have odd smell and taste

I have not noticed this often, but once in a while--like this morning's poached eggs--our eggs will have an odd smell and taste. They smell exactly like the smell you get when you scald a chicken to pluck it. (I've only done that once, but it was memorable.) I guess you'd describe it as gamey. Am I just smelling the chicken-ness of the egg, or should I be concerned? It's tolerable but not exactly pleasant. Thanks!

My brother gave his hens some left over salad that had a little dressing on it. Their eggs tasted nasty for days just from the bit of seasoning that was in the oil dressing. Not sure if you've been feeding scraps but always think first about ANY seasoning or spices.

No scraps recently, no new feed, no dewormer or antibiotics. When I cleaned out their coop the other day, a field mouse leaped out from under the warm bedding and scurried off. If he came back later and they caught him, they would definitely have eaten him. That's a possibility. Thanks everyone for all the feedback!